Mutation in transforming growth factor beta induced protein associated with granular corneal dystrophy type 1 reduces the proteolytic susceptibility through local structural stabilization.
Mutation in transforming growth factor beta induced protein associated with granular corneal dystrophy type 1 reduces the proteolytic susceptibility through local structural stabilization.
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DOI：
10.1016/j.bbapap.2013.10.008
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发表时间：
2013-12
影响因子：
3.2
通讯作者：
Nielsen, Niels Chr.
中科院分区：
文献类型：
--
作者：
Underhaug, Jan;Koldso, Heidi;Runager, Kasper;Nielsen, Jakob Toudahl;Sorensen, Charlotte S.;Kristensen, Torsten;Otzen, Daniel E.;Karring, Henrik;Malmendal, Anders;Schiott, Birgit;Enghild, Jan J.;Nielsen, Niels Chr.
关键词：
转化生长因子β诱导(TGFBI)基因的遗传性突变会导致以角膜中蛋白质沉积为特征的明显的角膜营养不良。我们在这里表明，与颗粒性角膜营养不良1型相关的蛋白(TGFBIp/角化上皮蛋白/βig-h3)的第四束蛋白1(FAS1-4)结构域的Arg555Trp突变体对热分解酶和胰蛋白酶的蛋白分解的敏感性显著低于WT结构域。WT和Arg555Trp突变体FAS1-4结构域的高分辨液态核磁共振显示除了555位附近的区域外，其他结构非常相似。Arg555Trp替换导致Trp555被埋在FAS1-4结构域的空的疏水空腔中。FAS1-4结构域核心的第一个热裂解蛋白裂解发生在Leu558的N端，与Arg555突变相邻。MD模拟表明，含有该切割位点的螺旋α3‘的C端在突变区域中灵活性较差，这解释了观察到的蛋白降解抗性。这种结构变化也改变了静电性质，这可能解释了突变体在体外与2，2，2-三氟乙醇聚集的倾向增加的原因。根据我们的结果，我们认为Arg555Trp突变扰乱了角膜TGFBIp的正常降解/周转，导致聚集，并通过静电相互作用增加聚集倾向。
Hereditary mutations in the transforming growth factor beta induced (TGFBI) gene cause phenotypically distinct corneal dystrophies characterized by protein deposition in cornea. We show here that the Arg555Trp mutant of the fourth fasciclin 1 (FAS1-4) domain of the protein (TGFBIp/keratoepithelin/βig-h3), associated with granular corneal dystrophy type 1, is significantly less susceptible to proteolysis by thermolysin and trypsin than the WT domain. High-resolution liquid-state NMR of the WT and Arg555Trp mutant FAS1-4 domains revealed very similar structures except for the region around position 555. The Arg555Trp substitution causes Trp555 to be buried in an otherwise empty hydrophobic cavity of the FAS1-4 domain. The first thermolysin cleavage in the core of the FAS1-4 domain occurs on the N-terminal side of Leu558 adjacent to the Arg555 mutation. MD simulations indicated that the C-terminal end of helix α3′ containing this cleavage site is less flexible in the mutant domain, explaining the observed proteolytic resistance. This structural change also alters the electrostatic properties, which may explain increased propensity of the mutant to aggregate in vitro with 2,2,2-trifluoroethanol. Based on our results we propose that the Arg555Trp mutation disrupts the normal degradation/turnover of corneal TGFBIp, leading to accumulation and increased propensity to aggregate through electrostatic interactions.
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影响因子：
3.9
作者：
Kannabiran, Chitra;Klintworth, Gordon K.
通讯作者：
Klintworth, Gordon K.
影响因子：
4.3
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Koldsø H;Noer P;Grouleff J;Autzen HE;Sinning S;Schiøtt B
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Schiøtt B
影响因子：
3.6
作者：
Ferguson, JW;Thoma, BS;LeBaron, RG
通讯作者：
LeBaron, RG
影响因子：
4.4
作者：
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通讯作者：
BROOKS, BR
影响因子：
4.4
作者：
JORGENSEN, WL;CHANDRASEKHAR, J;KLEIN, ML
通讯作者：
KLEIN, ML